SHIP'S MAGNETISM. 



303 



Imagine the vessel to be made of solid iron and consider the 

 transverse slice of iron which lies between the dotted lines in Fig. 



Fig. 12. 



13. When the bow points east or west (magnetic) the transverse 

 slice is magnetized as indicated by the letters N and S, and the 

 curved line ff, which represents a line of force due to the poles 

 N and S, shows that the field at C which is produced by the 



stern 



Fig. 13. 



magnetism of the transverse slice is towards the south. What is 

 here said concerning a given transverse slice of the ship is true 



